Thermally actuated ventilator



March 4, 1958 R. A. GERLITZ 2,825,275

' THERMALLY ACTUATED VENTILATOR Filed Jan. 27, 1955 ATTORNEYS.

Thisinvention relates to a thermally actuated ventilator. and particularly a ventilator such as is used in modern one-floor type industrial buildings covering large areas.

For many-years people concerned with the problems of first prevention and the minimization of fire damage have considered that it was essential to eliminate so far as possible any draft which could bring air to the fire and fan the flames. While this principle is undoubtedly sound in most situations, it has been found recently that in modern industrial buildings of the one-floor type which cover large floor areas, a fire produces a heavy accumulation of fumes and permits the heat to build up to such an extent that firemen cannot penetrate into the building in order to bring the fire under control. This danger was. vividly demonstrated in the course ofa tremendous fire in a large industrial plant within the last couple of years.

With the above considerations in view, it is an object of the present invention to provide an automatic roof ventilator which would open in the event of a fire automatically and permit smoke, fumes and heat to be exhausted from the building so as to make it possible for firemen to get into the building and get at the source of the fire.

It is another object of the invention to provide a roof ventilator which will normally be closed and which will open by the action of springs, and to prevent the operation of the springs by means of a fusible element so that in the event of a fire the fusible element will melt and the springs can operate to open the ventilator.

These and other objects of the invention which I shall now describe hereinafter or which will become apparent to those skilled in the art upon reading these specifications, I accomplish by that certain construction and arrangement of parts of which I shall now describe an exemplary embodiment.

Reference is made to the drawings forming a part hereof and in which:

Figure 1 is a plan view of a ventilator according to the present invention.

Figure 2 is a cross-sectional view of the same taken on the line 22 of Figure 1.

Figure 3 is an enlarged plan view showing the springs and their mounting.

Figure 4 is a fragmentary cross-sectional view taken on the line 44 of Figure 3 on a greatly enlarged. scale.

Figure 5 is a fragmentary perspective view of one of the springs, and

Figure 6 is a view similar to Figure 4, showing a modified link.

Briefly, in the practice of my invention I provide a roof ventilator which in general appearance and structure is substantially as shown in my earlier patent, No. 2,668,491 dated February 9, 1954. Since the details of the ventilator' construction are described in said patent, and since they form no part of the present invention, I shall not describe the general structure thereof. The only difference between the ventilator of my patent and the present veuti' United States Patent Patented Mar. 4, T958 lator is that I provide a spring mechanism for opening the damper blades and a particular link mechanism for holding the blades in closed position.

neiemng now more particularly to the drawings, the

ventilator is generally circular in shape, as described in.

my patent, or it may be rectangular it more convenient, and comprises the two roughly semi-circular damper blades to and 11 which are adapted to pivot upwardly as indicated by the arrows in broken lines in Figure 2. [he blades m and u are adapted to return in the solid line positlon of Figure 2 under the influence or gravity.

Transversely ol the ventilator, 1 provide a spring mounting bar indicated generally at 12 and which, at bestseen iii-Figure 3, comprises a tube 13 and a telescoping stub tube 1.4, by means of which the length or the [IlUUnthlg may oe ad usted tor ourerent diameter ventilators. 11'. will 7 be understood that for a given size of ventilator, ad ustatllllly may be fillmll'laleCl, and OI course a SEUD 110E COUld I is and aving at the other end anextension 19, a hooklike portion 20 and an actuating arm 21. The actuating arm 21 may terminate in a return bent portion 21a to prevent sticking and to make for smoother operation. i'he'helical portion r7 of each spring 18 slipped onto the member 13, as seen in Figure 3, and the hook portion 18 cooperates with a pin 19a to hold one end of each spring against rotation. The bias of the springs willtend to tnrow the arms 21 upwardly so as to lift the blades 10 and 11 to their broken line position of Figure 2. v

In order to hold the springs in inoperative position so that the blades 10 and 11 may remain in closed position under the influence of gravity, 1 provide a linkage, best seen in Figure 4.

As seen in Figure 4, I provide a pair of links 22 and 23, each provided with an eye 24, 25. A ring 26 may be secured integrally to the link 22 or it may be a separate ring. The links 22 and 23, and the ring 26 are held in assembled relationship by means of a fusible element 27 and an adjustable spacing jack 28, so that the members 22, 23, 26, 27 and 28 can be assembled into a unitary structure by slipping the link 23 into the ring 26 (if the ring 26 be integral with the link 22) or slipping the two links 22 and 23 into the ring 26 (if the ring 26 be separate), placing the fusible element 27 between the jaws of the links 22, 25 and the jack 28 between the links 22 and 23 on the other side of the ring 26. The ack 28 is simply unscrewed to the point where it locks the various elements together.

The structure just described is secured to the two springs by means of links 29 and 30. These links respectively pass through the eyes 24 and 25 and hook onto the portions 20 of the two springs and in the position of Figure 4 they hold the springs in inoperative position so that the parts occupy the position of Figure 2.

In the event of a fire when a certain desired temperature is reached, the element 27 fuses, whereupon the link 23 can immediately pivot in a clockwise direction so that the jack 28 falls out and the link 23 is pulled out of the link 26, whereupon the spring arms 21 operate to open the damper blades 10 and 11. If the ring 26 is a separate piece, it will simply fall off but the device will operate just as well if the ring 26 is integral with the link 22. A linkage as above described is suitable for larger ventilators and is commercially available.

A simpler linkage, suitable for smaller ventilators is shown intffigure 6, andieomprises two elements 3.1 andw32q a secured respectively to the portions 20 of the two springs. The parts 31 and 32 are telescoped together and held in assembly =by1 a: fu sible. material; .sothat; tun-den the. influence;

of heat;. the' two. parts simply separater 'lihetlink ofsfiigeure 6 is also commercially available: i I

From the foregoing description, it willi be: seenmthatzriI have provided. awveny simplexand fooL-proof; structurewhichtwillsautomatically operate inithereventsof. aafire to:

release the: springsito :cause; thezdamperfbladesato open.

It will be understood. that: various; modifications. may be made without: departing: frorrrthel spirit. of the, invert.-

tion and I therefore,.dor not .intenditolimit myself..except as set fourth in.the"claims which.follow..' v y Havingnow. fullydescnibedmy:inventionrwhat-L claim as newi and desire: to i secure by Letters; Patent: is z;

1.- In: a roof: ventilator :having a: pair of; hinged;dampen; blades. normally occupyingla closed positionrby'virtuq'of.

gravity, a spring mounting. ban disposedparallelto and between the hinge lines of said blades,, a; pair oftorsion bar and having at the other end a blade actuating extension, said blade actuating. extensions extending outwardly from said mounting bar in diametrically opposite directions, each bearing against the underside of one of said damper blades and urgingisaid blades to open position, and a linkage extendingbetween said actuating extensions, and holding. themtogether totprevent their operation,,said

linkage including a fusible element to renderitvoperative,

and arranged to fail upon destruction of said fusible element.

2 In a roof ventilator; a damper blade normally occu-- pying a closed position by virtue of gravity, but openable by an air stream passing through said ventilator, a mount manners;

springs each secured at one of- 1 its ends tosaid mounting in, member in, said, ventilator, a torsion spring mounted on said mounting member with one end fixed, the other end thereof bearing against the underside of said damper blade to urge it to open position against the force of gravity, and heat destructible means secured to said other end of said spring to prevent said spring from opening said damper until said heat destructible means is destroyed by heat.

3. In a roof ventilator, a pair of damper blades normally occupying a closed'position by virtue ofgravity, but

openable by an air stream passing through said ventilator, a mounting member associated with said ventilator, a pair of' torsiorrispringsmountedi on said mounting member, one end of each of said springs being fixed and the other end of each spring bearing against the underside of one of said damper blades, whereby said springs urge said damper blades to open position against the force of gravity,. and; heat destructiblemeans connecting thesaid other endsof. said springs toimrnobilize them and prevent them.

from opening said damperblades until said heat destructibleisrdestroyed by heat.

References Cited in the file of this patent UNITED- STATES PATENTS 

